ERBB2 and breast cancer: Moreover, the IRIS trial (NCT04383275) is currently assessing the potential efficacy of capecitabine as a chemotherapy partner for adjuvant trastuzumab in stage I HER2 + BC, and the single-arm phase II ADEPT trial is assessing the use of adjuvant endocrine therapy, pertuzumab, and trastuzumab in patients with HR + /HER2+ stage I BC (NCT04569747).